Power press



Jan. 26,1926. A 1,571,044

v A. v. DA cos'rA POWER PRESS Filed August 51 1922 Patented Jan. Z6, 1926.

UNITE@ OPPIC;

ARTHUR V. DA COSTA, OF PROVIDENCE, RHODEISLAND, ASSIG'NOR, BY MESNE AS- SIGNMENTS, T0 PROVIDENCE PRESS MACHINERY CO., INC., A CORPORATION OF RHODE ISLAND.

rownn zennss.

Application filed August 31, 1922. Serial No. 585,409.

To all wlw/m t may concern:

Be it; known that I, ARTHUR V. DA COSTA, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Power Presses, of which the following is a specification.

This invention relates to improvements in the construction of fluid pressure operated power presses adapted more particularly for use by jewelers for stamping out small pieces in the manufacture of jewelry and the like, but this press may be used for any other purpose for which it is adapted; and the object of this invention is to provide a press of this character which is simple, practical and inexpensive in construction, comprising a cylinder having a piston operatively mounted therein and carrying a plunger member, adjustable means being provided for limiting the extent of the working stroke of the piston and plunger.

A further object of the invention is to provide adjustable means for limiting the operating stroke of the valve whereby the speed of movement of the piston is nicely controlled. r

A still further object of the invention is to provide cushioning means for arresting the return stroke of the piston.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described, and particularly pointed; out in the appended claims. i

In the accompanying drawings:

Figure l is a sectional front elevation of the device.

Figure 2 is a side elevation of the device showing the supporting table partly in section.

Figure 3 is an end view of the valve showing the adjustable means for controlling the extent -of its opening and closing strokes.

l/Vith reference to the drawings, designates a table on which the Vmachine is mounted and ll the legs for support-ing the table. The press comprises essentially a cylinder l2 in which is operatively mounted a piston 18, the same having a boss lll which extends into a corresponding recess l5 in the hp cr end of the plunger member 16. This punger secured to the piston by means of screws 17, a space being left between the piston and the plunger for the reception of a leather packing 18. The plunger member is of a diameter smaller than that of the piston and the leather packing 18 fills the space about the outer end of the plunger and renders the piston tight against the lifting fluid pressure which enters through a port 19.

The lower end of the cylinder 12 is secured to a guide sleeve 20, which sleeve is supported on the standard 9 extending upward from the base 27 and through which sleeve 16 the plunger works and between this guide sleeve and the lower end ofthe cylinder is left a recess 21 in Vwhich the leather packing 22 litsto prevent the fluid pressure from flowing downwardly between the sleeve and the plunger. f

The.lower end of this plunger is provided with a recess 23 for the reception of theshank of a tool 24 which is secured in position by means of a binding screw 25, to cooperate with a die or other tool 26 which is supported on the base 27.

The upper portion of this plunger is provided with an elongated axially-disposed chamber 28 which is preferably formed square in cross section for the reception of a nut 29, a portion of which is also formed square to lit loosely in said chamber so as to prevent it from rotating therein.

It is found in practice necessary to be able to limit the extent of the downward stroke of this plunger, particularly when cutting tools are employed for cutting out the stock whereby the plunger will be arrested after the tool has passed through the work, and to accomplish this in a simple and effective way, I have provided an adjusting screw or threaded spindle 30, the lower end of which passes through the piston head and is threaded intothe nut 29, while the upper end extends through the cylinder head 31 and is threaded for a short distance to receive the binding or locking mem :ber 32, and to the upper end of this spindle is secured an operating wheel or handle 33.

A collar member 34: is formed on the spindle on the inside of the cylinder whereby by loosening the binding member the spindle may be rotated by the wheel to adjust the nut 29 in its chamber, either up or down on the spindle, after which the binding nut 32 is rotated by its handle 3.5 to Ijaar against the head oit the cylinder, to secure the spindle in adjusted position.

It is iound in practice ol' advantage to provide a cushioning means for arrestingi A the upward stroke olf the piston, and, therepiston and its plunger by air pressure, IV

have lormed a. channel 3S in the side wall. ot the cylinde and in this channel I hafve mounted a rotary valve 39 o1 the plug type, which is provided with a three-way port 40. A lever tl is connected tothe outer end ot the valve which is operated from the toot pedal 42 through a connecting rod Llf3.

The Huid pressure, preferably compressed air, is admitted through the supply pipe 45 to enter directly to the chamber 4G 4iorrned between the packings 18 and 22, to constantly act upon the comparatively small area of the piston, to move it in an upward direction and when the valve 4() is in the position shown in Figure l the pressure above the piston is released to escape through an exhaust pipe la thus permitting the pist0n to rise after having` performed an operating stroke.

lillhen another operating stroke is desired the foot of'y the. operator presses downwardly upon the lever l2 thus rotating; the valve causing its ports to. close the exhaust to pipe le and register with the pressure passageway leading to the inlet pipe. 45, whereby the pressure on the greater areal on the upper side ot the piston immediately ilprces it down against the pressure on the smaller area in chamber 416 to perform a working stroke and whenthis 'toot lever is released the valve mechanism is returned to the position illustrated in Figure l, by action ol. spring 59 to exhaust the pressui'e in the head ol: the cylinder and permit the plunger to litt, ready for another working stroke.

In some instances itis Yfound desirable lo limit, either' or both the openingand closing;` strokes ot the valve so as to control the volume ot' flowing,v pressure either into or out of the upper portion oli the cylinder and so limit the travelingV speed ot the piston stroke eitherrup or down, and to accomplish thisv in a simple and effective way, I have formed a pair ol ears 47 and 48 on this valve through which I have tapped stop screws lil and 50, which screws are adjustable endwise and are adapted to bring up against the surliace 5l on thecylinder and by adjusting them endwa ys the stroke of the valve may be nicely controlled to open the passageway to the desired extent either 'tor admitting` or discharging pressure therethrough. l

My improved power press is very simple and practical in its construction and el'lective in its operation and byA its use workmay be very rapidly operated upon, and the torce ot the blow nicely regulated.

The foregoing description is directed solely towards the construction illustrated, but I desire it'to be understood that l reserve the privilege ofresortin` to all the mechanical changes to which the device is susceptible, the invention beingy defined and limited only by the terms ot the appended claims.

I claim:

l. In a power press, a cylinder, a piston in said cylinder carrying a plunger iueinlier j )rovidedv'ith an elongated chamber, a slop nut slidably but' non-rotatably mounted iu said chamber, a threaded spindle extending.: through said cylinder head and said piston into said'nut, means whereby said spindle may be rotated to adjust said n ut thereon to limit the outward stroke 'ot the piston, and a valve for controlling the rei'iiprocalingg action of said piston.

Q. In a power press, a cylinder, a j;icssure operated piston insaid cylinder cari-vine a plunger member provided with :in elo ed chamber, a stop nut slidalgily but norrrol alably mounted in said chamber, an adjusting screw extending through said cylinder head and said piston into said nut, means wliereby said screw .may be'rotated to adjust said nuiv thereon to limit the outward stroke ol the piston, meansglor binding` said screw in adjusted position, and a va.y ve 'i'or controlling the reciprocating action 0l' said piston.

3. In a power press, a cylinder having); a piston operatively mounted therein and "au rying a plunger member, a spindle esteinlin nY through said cylinder into said pistou, an adjustable stop member on said spindle Yl'or limiting?,l the extent o'li the outward stroke ell said piston, a valve 'tor controlling the admission and discharge o ll pressure to and v'from the upper side ot the pistou, ports l'or admitting' a constant pressure to return the piston aliter each working;` stroke, and means tor cushioning the return stroke ot the piston.

In testimony whereo't'l atlix my signature.

ARTHUR V. Dit GOS'VVA. 

